1). Field of the Invention
The present invention relates to an opener for a grain drill, planter or similar agricultural implement which deposits material such as seed or fertilizer in furrow and then closes the furrow.
2). Related Art
An opener arrangement for depositing seed or fertilizer in a furrow such as shown in U.S. Pat. No. 4,760,806 Bigbee et al includes an angled disk having a depth control wheel adjacent the leading face of the disk and a seed boot assembly including a seed tube on the trailing side of the disk. The wheel provides depth adjustment, cleans the leading face of the disk, and limits soil lifting and throw adjacent the disk. One or more closing or press wheels trail the disk to move soil and close the furrow over the material deposited from the seed tube. Such openers limit soil disturbance, but often a portion of the seed.boot or runner operates soil just outside the trench which increases soil disturbance, power requirements, wear and seed placement inconsistencies. The leading side wheel axis is close to the disk hub so the wheel operates forwardly of the area where the disk exits the soil so soil lift at the exit point can be a problem, particularly when the operating depth of the disk is increased. If the boot rides outside the furrow, tracking problems are also increased. An opener arrangement with a seed boot that remains substantially in the shadow of the disk when viewed from the forward direction is shown in U.S. Pat. No. 5,595,130 Baugher. In most single disk arrangements, however, a portion of the boot, as viewed from the side of the opener, is outside the periphery of the disk and is subject to damage when objects such as rocks are encountered in the ground.
With some opener arrangements, residue frequently wedges between adjacent openers, between the boot and the opener disk hub or the disk, or between the disk and one of the trailing wheels. The trailing wheel increases the overall length of the opener and does not track well when the implement is turned from the forward direction. The rearward wheel location requires a longer and heavier support arm arrangement less responsive to rapid changes in ground contours.
A further problem exists when efforts to reduce the size of the seed boot so the boot is within in the shadow of the opener disk results in a narrowed lower portion on the material delivery tube, particularly when the disk angle is approximately five degrees or less. Maintaining a high material rate is particularly important for high speed operation, and the narrowed lower portion of the tube reduces the rate at which material can be delivered to the furrow. Further, material delivery uniformity as well as rate may also be adversely affected by use of delivery tubes such as shown in the aforementioned U.S. Pat. No. 4,760,806 having other than a substantially vertical component. The problem of reduced delivery rate is further compounded when the tube is curved.
When an opener is depositing seeds in a furrow, placing the seeds at a constant depth is important for uniform germination and optimum plant growth. Often opener arrangements have closing or press wheels that trail the seed boot a substantial distance. The actual closing of the furrow occurs some time after the deposited material reaches the bottom of the furrow, and of the material has time to bounce from the bottom of the furrow and as a result the material is placed shallower than desired. At times, seeds can actually bounce completely out of the furrow so they lie on top of the ground and do not germinate. The trend toward higher speed planting and fertilizing for increased productivity increases the problem of material bounce and soil throw. Also, the seed boot runner in some presently available openers (see O of the prior art examples of FIGS. 11 and 12) can actually form a slight shelf or ridge (R) in the side of the furrow (F), especially when operating relatively deeply, and seed can lodge on the ridge rather than at the bottom of the furrow. A further problem arises when soil disturbed by the unwanted shelving or ridging process falls into the bottom of the furrow and affects seed placement.
Various seed bounce flaps or seed firming attachments such as shown in U.S. Pat. Nos. 5,092,255; 5,673,638 and 5,918,557 have been made available to limit bounce or firm the material in the furrow, but these result in added components, expense and maintenance and sometimes fail to completely solve the problems caused by bounce and ridging. Some wheel structures can decrease trash clearance and be a source of blockages, particularly in fields having high trash content.
It is therefore an object of the present invention to provide an improved opener assembly. It is a further object to provide such an opener assembly which overcomes most or all of the aforementioned problems.
It is a further object of the present invention to provide an improved opener assembly particularly useful for high speed fertilizing or seeding operations. It is another object to provide such an assembly which is compact and has a narrow profile. It is a further object to provide such an assembly which reduces material bounce in the furrow.
It is a further object of the present invention to provide an improved opener assembly which has a profile wherein the material placement boot or runner is located within the shadow of the opener disk when viewed in the forward direction and within the periphery of the disk when viewed from the side to provide protection against damage from objects in the field. It is another object to provide such an assembly having a narrow profile and improved placement characteristics without sacrificing high material throughput capabilities.
It is still another object of the present invention to provide an improved opener assembly with a closing wheel arrangement which facilitates better material placement and higher speed operation than at least most previously available opener assemblies. It is another object to provide such an assembly that closes the furrow immediately after the material reaches the bottom of the furrow to eliminate bounce. It is yet another object to provide such an arrangement which closes the furrow from the top down and pushes the deposited material to the bottom of the furrow.
A further object of the present invention is to provide an opener with a closing wheel assembly which is compact, relatively light, and provides excellent trash clearing capabilities. It is another object to provide such an assembly which has a short support arm for compactness, good trailing characteristics and fast reaction time. It is yet another object to provide an opener with a closing system including a depth control and disk scraping wheel on one side of the disk cooperating with a closing wheel on the opposite side of the disk, both wheels located just behind an opener boot to close the furrow immediately after material is deposited in the furrow. It is still another object to provide such an opener which is less prone to blockages and which is ideally suited for narrow row spacings in high residue conditions.
It is another object of the invention to provide an improved opener assembly having a delivery tube arrangement with a high throughput for high speed operation. It is a further object to provide such an assembly which is compact and includes a unique compact hinge construction for biasing the delivery tube towards the furrow opening disk. It is yet another object to provide such an assembly having a high material throughput capability while maintaining the material delivery structure within the shadow of a single angled opener disk. It is another object to provide such an assembly which has an opener boot cross section which closely matches the cross section of the furrow formed by the opener disk to maximize material delivery output size and furrow wall holding capability while minimizing power requirements, soil disturbance and wear.
An opener assembly constructed in accordance with the teachings of the present invention includes a single opener disk rotatably supported from a drawbar and angled approximately five degrees from the forward direction to define a shadow area behind the trailing surface of the disk and open a furrow in the ground. A material placement boot and specially shaped material delivery tube are supported adjacent the trailing surface substantially entirely within the shadow of the disk and have profiles conforming to the furrow profile. The boot holds the furrow open while the delivery tube, which is vertical and positioned rearwardly of the disk axis, delivers seed to the bottom of the furrow. The delivery tube is substantially straight and has an upper portion with a round cross section which gradually changes to an elliptical cross section towards the outlet to remain within the shadow while retaining throughput capabilities that allow operational speeds well in excess of five miles per hour (8 km/hr). Conforming the boot to the furrow profile maximizes size for good soil holding and throughput while limiting soil disturbance, boot wear and power requirements. A compact tube pivot and horizontally disposed U-shaped spring arrangement fit into a limited space area to bias the boot and tube towards the disk.
To close the furrow immediately after material is deposited in the furrow bottom, first and second wheels are supported on opposite sides of the disk to urge soil downwardly behind the outlet of the delivery tube immediately after the material is deposited. The furrow walls are collapsed from the top down and provide a soil wave ahead of the wheels. The soil action caused by the closely spaced wheels pushes the material to the furrow bottom and results in a very constant material depth. The immediate soil action also prevents material bounce and results in substantially better placement control than at least most opener assemblies having closing wheels that trail the opener disk and therefore provide delayed closing action. The close placement of the wheel on the trailing side of the opener disk reduces opener assembly length, provides better tracking, and reduces the weight of the wheel arm so the trailing side wheel, which is adjustably biased into contact with the soil primarily by spring action rather than weight, can respond more quickly to ground contours. When anhydrous ammonia or a similar material is placed in the soil by the opener, the advantageous closing action provided by the unique wheel. arrangement immediately seals the furrow to prevent loss of gas.
The depth adjusting wheel on the leading side of the angled opener disk is supported behind the disk axis by an arm assembly which provides convenient depth adjustment from the forward end of the drawbar. The leading side wheel pushes soil around the trailing edge of the disk to collapse the furrow wall immediately after material is deposited in the furrow and provides a scraping action against the disk and prevents soil from lifting out of the furrow as the disk rotates out of the ground, particularly in wet sticky soil conditions and when the disk is set for deep operation,. By moving the wheel rearwardly from a conventional position such as exemplified in the aforementioned U.S. Pat. No. 4,760,806, a smaller disk can be utilized to provide deeper ground penetration while retaining good resistance to soil lifting in the area where the disk exits the soil. The leading side wheel and the closing wheel are both angled in the same direction for improved movement of trash between the wheels to prevent clogging. Better overall machine trash flow, particularly in high trash conditions, is another benefit of having the wheels angled in the same direction. By utilizing the like-angled wheels and staggering the spacing of the opener assemblies, trash from one opener is prevented from impinging directly on an adjacent opener.
These and other objects, features and advantages of the present invention will become apparent to one skilled in the art upon reading the following detailed description in view of the drawings.